2 * sllin.c - serial line LIN interface driver (using tty line discipline)
4 * This file is derived from drivers/net/can/slcan.c
5 * slcan.c Author: Oliver Hartkopp <socketcan@hartkopp.net>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307. You can also get it
20 * at http://www.gnu.org/licenses/gpl.html
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
35 * Send feedback to <socketcan-users@lists.berlios.de>
39 #define DEBUG 1 /* Enables pr_debug() printouts */
41 #include <linux/module.h>
42 #include <linux/moduleparam.h>
44 #include <asm/system.h>
45 #include <linux/uaccess.h>
46 #include <linux/bitops.h>
47 #include <linux/string.h>
48 #include <linux/tty.h>
49 #include <linux/errno.h>
50 #include <linux/netdevice.h>
51 #include <linux/skbuff.h>
52 #include <linux/rtnetlink.h>
53 #include <linux/if_arp.h>
54 #include <linux/if_ether.h>
55 #include <linux/sched.h>
56 #include <linux/delay.h>
57 #include <linux/init.h>
58 #include <linux/can.h>
59 #include <linux/kthread.h>
60 #include <linux/hrtimer.h>
61 #include "linux/lin_bus.h"
63 /* Should be in include/linux/tty.h */
65 /* -------------------------------- */
67 static __initdata const char banner[] =
68 KERN_INFO "sllin: serial line LIN interface driver\n";
70 MODULE_ALIAS_LDISC(N_SLLIN);
71 MODULE_DESCRIPTION("serial line LIN interface");
72 MODULE_LICENSE("GPL");
75 #define SLLIN_MAGIC 0x53CA
76 /* #define BREAK_BY_BAUD */
78 static int maxdev = 10; /* MAX number of SLLIN channels;
79 This can be overridden with
80 insmod sllin.ko maxdev=nnn */
81 module_param(maxdev, int, 0);
82 MODULE_PARM_DESC(maxdev, "Maximum number of sllin interfaces");
84 /* maximum buffer len to store whole LIN message*/
85 #define SLLIN_DATA_MAX 8
86 #define SLLIN_BUFF_LEN (1 /*break*/ + 1 /*sync*/ + 1 /*ID*/ + \
87 SLLIN_DATA_MAX + 1 /*checksum*/)
88 #define SLLIN_BUFF_BREAK 0
89 #define SLLIN_BUFF_SYNC 1
90 #define SLLIN_BUFF_ID 2
91 #define SLLIN_BUFF_DATA 3
93 #define SLLIN_SAMPLES_PER_CHAR 10
94 #define SLLIN_CHARS_TO_TIMEOUT 12
100 SLSTATE_RESPONSE_WAIT, /* Wait for response */
101 SLSTATE_RESPONSE_WAIT_BUS, /* Wait for response from LIN bus
102 only (CAN frames from network stack
103 are not processed in this moment) */
104 SLSTATE_RESPONSE_SENT,
107 struct sllin_conf_entry {
108 int dlc; /* Length of data in LIN frame */
109 canid_t frame_fl; /* LIN frame flags. Passed from userspace as
111 u8 data[8]; /* LIN frame data payload */
117 /* Various fields. */
118 struct tty_struct *tty; /* ptr to TTY structure */
119 struct net_device *dev; /* easy for intr handling */
122 /* LIN message buffer and actual processed data counts */
123 unsigned char rx_buff[SLLIN_BUFF_LEN]; /* LIN Rx buffer */
124 unsigned char tx_buff[SLLIN_BUFF_LEN]; /* LIN Tx buffer */
125 int rx_expect; /* expected number of Rx chars */
126 int rx_lim; /* maximum Rx chars for current frame */
127 int rx_cnt; /* message buffer Rx fill level */
128 int tx_lim; /* actual limit of bytes to Tx */
129 int tx_cnt; /* number of already Tx bytes */
130 char lin_master; /* node is a master node */
131 int lin_baud; /* LIN baudrate */
132 int lin_state; /* state */
133 char id_to_send; /* there is ID to be sent */
134 char data_to_send; /* there are data to be sent */
135 char resp_len_known; /* Length of the response is known */
137 unsigned long flags; /* Flag values/ mode etc */
138 #define SLF_INUSE 0 /* Channel in use */
139 #define SLF_ERROR 1 /* Parity, etc. error */
140 #define SLF_RXEVENT 2 /* Rx wake event */
141 #define SLF_TXEVENT 3 /* Tx wake event */
142 #define SLF_MSGEVENT 4 /* CAN message to sent */
143 #define SLF_TMOUTEVENT 5 /* Timeout on received data */
146 struct task_struct *kwthread;
147 wait_queue_head_t kwt_wq; /* Wait queue used by kwthread */
148 struct hrtimer rx_timer; /* RX timeout timer */
149 ktime_t rx_timer_timeout; /* RX timeout timer value */
150 struct sk_buff *tx_req_skb; /* Socket buffer with CAN frame
151 received from network stack*/
153 /* List with configurations for each of 0 to LIN_ID_MAX LIN IDs */
154 struct sllin_conf_entry linfr_cache[LIN_ID_MAX + 1];
157 static struct net_device **sllin_devs;
158 static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf);
161 /* Values of two parity bits in LIN Protected
162 Identifier for each particular LIN ID */
163 const unsigned char sllin_id_parity_table[] = {
164 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40,
165 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0,
166 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80,
167 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00,
168 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0,
169 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40,
170 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00,
171 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80
175 * sltty_change_speed() -- Change baudrate of Serial device belonging
178 * @tty: Pointer to TTY to change speed for.
179 * @speed: Integer value of new speed. It is possible to
180 * assign non-standard values, i.e. those which
181 * are not defined in termbits.h.
183 static int sltty_change_speed(struct tty_struct *tty, unsigned speed)
185 struct ktermios old_termios;
188 mutex_lock(&tty->termios_mutex);
190 old_termios = *(tty->termios);
192 cflag = CS8 | CREAD | CLOCAL | HUPCL;
193 cflag &= ~(CBAUD | CIBAUD);
195 tty->termios->c_cflag = cflag;
196 tty->termios->c_oflag = 0;
197 tty->termios->c_lflag = 0;
199 /* Enable interrupt when UART-Break or Framing error received */
200 tty->termios->c_iflag = BRKINT | INPCK;
202 tty_encode_baud_rate(tty, speed, speed);
204 if (tty->ops->set_termios)
205 tty->ops->set_termios(tty, &old_termios);
207 mutex_unlock(&tty->termios_mutex);
212 /* Send one can_frame to the network layer */
213 static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len)
220 if (cf.can_dlc > 0) {
221 memcpy(&cf.data, data, cf.can_dlc);
224 skb = dev_alloc_skb(sizeof(struct can_frame));
229 skb->protocol = htons(ETH_P_CAN);
230 skb->pkt_type = PACKET_BROADCAST;
231 skb->ip_summed = CHECKSUM_UNNECESSARY;
232 memcpy(skb_put(skb, sizeof(struct can_frame)),
233 &cf, sizeof(struct can_frame));
236 sl->dev->stats.rx_packets++;
237 sl->dev->stats.rx_bytes += cf.can_dlc;
241 * sll_bump() -- Send data of received LIN frame (existing in sl->rx_buff)
246 static void sll_bump(struct sllin *sl)
248 sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK,
249 sl->rx_buff + SLLIN_BUFF_DATA,
250 sl->rx_cnt - SLLIN_BUFF_DATA - 1); /* without checksum */
254 * Called by the driver when there's room for more data. If we have
255 * more packets to send, we send them here.
257 static void sllin_write_wakeup(struct tty_struct *tty)
261 struct sllin *sl = (struct sllin *) tty->disc_data;
263 /* First make sure we're connected. */
264 if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
267 if (sl->lin_state != SLSTATE_BREAK_SENT)
268 remains = sl->tx_lim - sl->tx_cnt;
270 remains = SLLIN_BUFF_BREAK + 1 - sl->tx_cnt;
273 actual = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt,
274 sl->tx_cnt - sl->tx_lim);
275 sl->tx_cnt += actual;
277 if (sl->tx_cnt < sl->tx_lim) {
278 pr_debug("sllin: sllin_write_wakeup sent %d, "
279 "remains %d, waiting\n",
280 sl->tx_cnt, sl->tx_lim - sl->tx_cnt);
285 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
286 set_bit(SLF_TXEVENT, &sl->flags);
287 wake_up(&sl->kwt_wq);
289 pr_debug("sllin: sllin_write_wakeup sent %d, wakeup\n", sl->tx_cnt);
293 * sll_xmit() -- Send a can_frame to a TTY queue.
295 * @skb: Pointer to Socket buffer to be sent.
296 * @dev: Network device where @skb will be sent.
298 static netdev_tx_t sll_xmit(struct sk_buff *skb, struct net_device *dev)
300 struct sllin *sl = netdev_priv(dev);
301 struct can_frame *cf;
303 if (skb->len != sizeof(struct can_frame))
306 spin_lock(&sl->lock);
307 if (!netif_running(dev)) {
308 printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name);
311 if (sl->tty == NULL) {
315 cf = (struct can_frame *) skb->data;
316 if (cf->can_id & LIN_CTRL_FRAME) {
317 sllin_configure_frame_cache(sl, cf);
318 goto free_out_unlock;
321 netif_stop_queue(sl->dev);
323 sl->tx_req_skb = skb;
324 set_bit(SLF_MSGEVENT, &sl->flags);
325 wake_up(&sl->kwt_wq);
326 spin_unlock(&sl->lock);
331 spin_unlock(&sl->lock);
338 /******************************************
339 * Routines looking at netdevice side.
340 ******************************************/
342 /* Netdevice UP -> DOWN routine */
343 static int sll_close(struct net_device *dev)
345 struct sllin *sl = netdev_priv(dev);
347 spin_lock_bh(&sl->lock);
349 /* TTY discipline is running. */
350 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
352 netif_stop_queue(dev);
355 spin_unlock_bh(&sl->lock);
360 /* Netdevice DOWN -> UP routine */
361 static int sll_open(struct net_device *dev)
363 struct sllin *sl = netdev_priv(dev);
365 pr_debug("sllin: %s() invoked\n", __FUNCTION__);
370 sl->flags &= (1 << SLF_INUSE);
371 netif_start_queue(dev);
375 /* Hook the destructor so we can free sllin devs at the right point in time */
376 static void sll_free_netdev(struct net_device *dev)
378 int i = dev->base_addr;
380 sllin_devs[i] = NULL;
383 static const struct net_device_ops sll_netdev_ops = {
384 .ndo_open = sll_open,
385 .ndo_stop = sll_close,
386 .ndo_start_xmit = sll_xmit,
389 static void sll_setup(struct net_device *dev)
391 dev->netdev_ops = &sll_netdev_ops;
392 dev->destructor = sll_free_netdev;
394 dev->hard_header_len = 0;
396 dev->tx_queue_len = 10;
398 dev->mtu = sizeof(struct can_frame);
399 dev->type = ARPHRD_CAN;
401 /* New-style flags. */
402 dev->flags = IFF_NOARP;
403 dev->features = NETIF_F_NO_CSUM;
406 /******************************************
407 Routines looking at TTY side.
408 ******************************************/
410 static void sllin_receive_buf(struct tty_struct *tty,
411 const unsigned char *cp, char *fp, int count)
413 struct sllin *sl = (struct sllin *) tty->disc_data;
415 pr_debug("sllin: sllin_receive_buf invoked\n");
417 if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
420 /* Read the characters out of the buffer */
423 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
424 sl->dev->stats.rx_errors++;
426 pr_debug("sllin: sllin_receive_buf char 0x%02x ignored "
427 "due marker 0x%02x, flags 0x%lx\n",
428 *cp, *(fp-1), sl->flags);
434 if (sl->rx_cnt < SLLIN_BUFF_LEN) {
435 #ifndef BREAK_BY_BAUD
436 /* We didn't receive Break character */
437 if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
438 sl->rx_buff[sl->rx_cnt++] = 0x00;
441 pr_debug("sllin: LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
442 sl->rx_buff[sl->rx_cnt++] = *cp++;
446 if (sl->rx_cnt >= sl->rx_expect) {
447 set_bit(SLF_RXEVENT, &sl->flags);
448 wake_up(&sl->kwt_wq);
449 pr_debug("sllin: sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
451 pr_debug("sllin: sllin_receive_buf count %d, waiting\n", sl->rx_cnt);
455 /*****************************************
456 * sllin message helper routines
457 *****************************************/
459 * sllin_report_error() -- Report an error by sending CAN frame
460 * with particular error flag set in can_id
463 * @err: Error flag to be sent.
465 void sllin_report_error(struct sllin *sl, int err)
468 case LIN_ERR_CHECKSUM:
469 sl->dev->stats.rx_crc_errors++;
472 case LIN_ERR_RX_TIMEOUT:
473 sl->dev->stats.rx_errors++;
477 sllin_send_canfr(sl, 0 | CAN_EFF_FLAG |
478 (err & ~LIN_ID_MASK), NULL, 0);
482 * sllin_configure_frame_cache() -- Configure particular entry in linfr_cache
485 * @cf: Pointer to CAN frame sent to this driver
486 * holding configuration information
488 static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf)
490 struct sllin_conf_entry *sce;
491 if (!(cf->can_id & LIN_ID_CONF))
494 sce = &sl->linfr_cache[cf->can_id & LIN_ID_MASK];
495 pr_debug("sllin: Setting frame cache with EFF CAN frame. "
496 "LIN ID = %d\n", cf->can_id & LIN_ID_MASK);
498 sce->dlc = cf->can_dlc;
499 if (sce->dlc > SLLIN_DATA_MAX)
500 sce->dlc = SLLIN_DATA_MAX;
502 sce->frame_fl = (cf->can_id & ~LIN_ID_MASK) & CAN_EFF_MASK;
503 memcpy(sce->data, cf->data, cf->can_dlc);
509 * sllin_checksum() -- Count checksum for particular data
511 * @data: Pointer to the buffer containing whole LIN
512 * frame (i.e. including break and sync bytes).
513 * @length: Length of the buffer.
514 * @enhanced_fl: Flag determining whether Enhanced or Classic
515 * checksum should be counted.
517 static inline unsigned sllin_checksum(unsigned char *data, int length, int enhanced_fl)
528 for (; i < length; i++) {
537 #define SLLIN_STPMSG_RESPONLY (1) /* Message will be LIN Response only */
538 #define SLLIN_STPMSG_CHCKSUM_CLS (1 << 1)
539 #define SLLIN_STPMSG_CHCKSUM_ENH (1 << 2)
541 int sllin_setup_msg(struct sllin *sl, int mode, int id,
542 unsigned char *data, int len)
544 if (id > LIN_ID_MASK)
547 if (!(mode & SLLIN_STPMSG_RESPONLY)) {
551 sl->rx_lim = SLLIN_BUFF_LEN;
554 sl->tx_buff[SLLIN_BUFF_BREAK] = 0;
555 sl->tx_buff[SLLIN_BUFF_SYNC] = 0x55;
556 sl->tx_buff[SLLIN_BUFF_ID] = id | sllin_id_parity_table[id];
557 sl->tx_lim = SLLIN_BUFF_DATA;
559 if ((data != NULL) && len) {
561 memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len);
562 sl->tx_buff[sl->tx_lim++] = sllin_checksum(sl->tx_buff,
563 sl->tx_lim, mode & SLLIN_STPMSG_CHCKSUM_ENH);
566 sl->rx_lim = SLLIN_BUFF_DATA + len + 1;
572 int sllin_send_tx_buff(struct sllin *sl)
574 struct tty_struct *tty = sl->tty;
579 if (sl->lin_state != SLSTATE_BREAK_SENT)
580 remains = sl->tx_lim - sl->tx_cnt;
584 remains = sl->tx_lim - sl->tx_cnt;
587 res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
595 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
596 res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
598 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
606 pr_debug("sllin: sllin_send_tx_buff sent %d, remains %d\n",
607 sl->tx_cnt, remains);
613 int sllin_send_break(struct sllin *sl)
615 struct tty_struct *tty = sl->tty;
616 unsigned long break_baud;
619 break_baud = ((sl->lin_baud * 2) / 3);
620 sltty_change_speed(tty, break_baud);
622 tty->ops->flush_buffer(tty);
623 sl->rx_cnt = SLLIN_BUFF_BREAK;
625 sl->rx_expect = SLLIN_BUFF_BREAK + 1;
626 sl->lin_state = SLSTATE_BREAK_SENT;
628 res = sllin_send_tx_buff(sl);
630 sl->lin_state = SLSTATE_IDLE;
636 #else /* BREAK_BY_BAUD */
638 int sllin_send_break(struct sllin *sl)
640 struct tty_struct *tty = sl->tty;
642 unsigned long break_baud;
643 unsigned long usleep_range_min;
644 unsigned long usleep_range_max;
646 break_baud = ((sl->lin_baud * 2) / 3);
647 sl->rx_cnt = SLLIN_BUFF_BREAK;
648 sl->rx_expect = SLLIN_BUFF_BREAK + 1;
649 sl->lin_state = SLSTATE_BREAK_SENT;
651 /* Do the break ourselves; Inspired by
652 http://lxr.linux.no/#linux+v3.1.2/drivers/tty/tty_io.c#L2452 */
653 retval = tty->ops->break_ctl(tty, -1);
658 usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR) / break_baud;
659 usleep_range_max = usleep_range_min + 50;
660 usleep_range(usleep_range_min, usleep_range_max);
662 retval = tty->ops->break_ctl(tty, 0);
663 usleep_range_min = (1000000l * 1 /* 1 bit */) / break_baud;
664 usleep_range_max = usleep_range_min + 30;
665 usleep_range(usleep_range_min, usleep_range_max);
667 tty->ops->flush_buffer(tty);
669 sl->tx_cnt = SLLIN_BUFF_SYNC;
671 pr_debug("sllin: Break sent.\n");
672 set_bit(SLF_RXEVENT, &sl->flags);
673 wake_up(&sl->kwt_wq);
677 #endif /* BREAK_BY_BAUD */
680 static enum hrtimer_restart sllin_rx_timeout_handler(struct hrtimer *hrtimer)
682 struct sllin *sl = container_of(hrtimer, struct sllin, rx_timer);
684 sllin_report_error(sl, LIN_ERR_RX_TIMEOUT);
685 set_bit(SLF_TMOUTEVENT, &sl->flags);
686 wake_up(&sl->kwt_wq);
688 return HRTIMER_NORESTART;
692 * sllin_rx_validate() -- Validate received frame, i,e. check checksum
696 static int sllin_rx_validate(struct sllin *sl)
701 unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1];
702 struct sllin_conf_entry *scf;
704 actual_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
705 scf = &sl->linfr_cache[actual_id];
707 ext_chcks_fl = scf->frame_fl & LIN_CHECKSUM_EXTENDED;
709 if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) !=
712 /* Type of checksum is configured for particular frame */
716 if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1,
717 !ext_chcks_fl) != rec_chcksm) {
726 /*****************************************
727 * sllin_kwthread - kernel worker thread
728 *****************************************/
730 int sllin_kwthread(void *ptr)
732 struct sllin *sl = (struct sllin *)ptr;
733 struct tty_struct *tty = sl->tty;
734 struct sched_param schparam = { .sched_priority = 40 };
735 int tx_bytes = 0; /* Used for Network statistics */
738 pr_debug("sllin: sllin_kwthread started.\n");
739 sched_setscheduler(current, SCHED_FIFO, &schparam);
741 clear_bit(SLF_ERROR, &sl->flags);
742 sltty_change_speed(tty, sl->lin_baud);
744 while (!kthread_should_stop()) {
745 struct can_frame *cf;
748 u8 lin_data_buff[SLLIN_DATA_MAX];
751 if ((sl->lin_state == SLSTATE_IDLE) && sl->lin_master &&
753 if(sllin_send_break(sl) < 0) {
754 /* error processing */
758 wait_event_killable(sl->kwt_wq, kthread_should_stop() ||
759 test_bit(SLF_RXEVENT, &sl->flags) ||
760 test_bit(SLF_TXEVENT, &sl->flags) ||
761 test_bit(SLF_TMOUTEVENT, &sl->flags) ||
762 (((sl->lin_state == SLSTATE_IDLE) ||
763 (sl->lin_state == SLSTATE_RESPONSE_WAIT))
764 && test_bit(SLF_MSGEVENT, &sl->flags)));
766 if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
767 pr_debug("sllin: sllin_kthread RXEVENT\n");
770 if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) {
771 pr_debug("sllin: sllin_kthread TXEVENT\n");
774 if (test_and_clear_bit(SLF_TMOUTEVENT, &sl->flags)) {
775 pr_debug("sllin: sllin_kthread TMOUTEVENT\n");
778 sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
781 sl->id_to_send = false;
782 sl->data_to_send = false;
784 sl->lin_state = SLSTATE_IDLE;
787 switch (sl->lin_state) {
789 if (!test_bit(SLF_MSGEVENT, &sl->flags))
792 cf = (struct can_frame *)sl->tx_req_skb->data;
794 /* SFF RTR CAN frame -> LIN header */
795 if (cf->can_id & CAN_RTR_FLAG) {
796 spin_lock(&sl->lock);
797 pr_debug("sllin: %s: RTR SFF CAN frame, ID = %x\n",
798 __FUNCTION__, cf->can_id & LIN_ID_MASK);
800 /* Is there Slave response in linfr_cache to be sent? */
801 if ((sl->linfr_cache[cf->can_id & LIN_ID_MASK].frame_fl &
803 && (sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc > 0)) {
805 pr_debug("sllin: Sending LIN response from linfr_cache\n");
806 lin_data = sl->linfr_cache[cf->can_id & LIN_ID_MASK].data;
807 lin_dlc = sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc;
808 if (lin_dlc > SLLIN_DATA_MAX)
809 lin_dlc = SLLIN_DATA_MAX;
810 memcpy(lin_data_buff, lin_data, lin_dlc);
811 lin_data = lin_data_buff;
814 lin_dlc = sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc;
816 spin_unlock(&sl->lock);
817 } else { /* SFF NON-RTR CAN frame -> LIN header + LIN response */
818 pr_debug("sllin: %s: NON-RTR SFF CAN frame, ID = %x\n",
819 __FUNCTION__, (int)cf->can_id & LIN_ID_MASK);
822 lin_dlc = cf->can_dlc;
823 if (lin_dlc > SLLIN_DATA_MAX)
824 lin_dlc = SLLIN_DATA_MAX;
828 if (sllin_setup_msg(sl, 0, cf->can_id & LIN_ID_MASK,
829 lin_data, lin_dlc) != -1) {
831 sl->id_to_send = true;
832 sl->data_to_send = (lin_data != NULL) ? true : false;
833 sl->resp_len_known = (lin_dlc > 0) ? true : false;
834 sl->dev->stats.tx_packets++;
835 sl->dev->stats.tx_bytes += tx_bytes;
838 clear_bit(SLF_MSGEVENT, &sl->flags);
839 kfree_skb(sl->tx_req_skb);
840 netif_wake_queue(sl->dev);
841 hrtimer_start(&sl->rx_timer,
842 ktime_add(ktime_get(), sl->rx_timer_timeout),
846 case SLSTATE_BREAK_SENT:
848 if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
851 res = sltty_change_speed(tty, sl->lin_baud);
854 sl->lin_state = SLSTATE_ID_SENT;
855 sllin_send_tx_buff(sl);
858 case SLSTATE_ID_SENT:
859 hrtimer_cancel(&sl->rx_timer);
860 sl->id_to_send = false;
861 if (sl->data_to_send) {
862 sllin_send_tx_buff(sl);
863 sl->lin_state = SLSTATE_RESPONSE_SENT;
864 sl->rx_expect = sl->tx_lim;
865 goto slstate_response_sent;
867 if (sl->resp_len_known) {
868 sl->rx_expect = sl->rx_lim;
870 sl->rx_expect = SLLIN_BUFF_DATA + 2;
872 sl->lin_state = SLSTATE_RESPONSE_WAIT;
873 /* If we don't receive anything, timer will "unblock" us */
874 hrtimer_start(&sl->rx_timer,
875 ktime_add(ktime_get(), sl->rx_timer_timeout),
877 goto slstate_response_wait;
881 case SLSTATE_RESPONSE_WAIT:
882 slstate_response_wait:
883 if (test_bit(SLF_MSGEVENT, &sl->flags)) {
884 unsigned char *lin_buff;
885 cf = (struct can_frame *)sl->tx_req_skb->data;
887 lin_buff = (sl->lin_master) ? sl->tx_buff : sl->rx_buff;
888 if (cf->can_id == (lin_buff[SLLIN_BUFF_ID] & LIN_ID_MASK)) {
889 hrtimer_cancel(&sl->rx_timer);
890 pr_debug("sllin: received LIN response in a CAN frame.\n");
891 if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY,
892 cf->can_id & LIN_ID_MASK,
893 cf->data, cf->can_dlc) != -1) {
895 sl->rx_expect = sl->tx_lim;
896 sl->data_to_send = true;
897 sl->dev->stats.tx_packets++;
898 sl->dev->stats.tx_bytes += tx_bytes;
900 if (!sl->lin_master) {
901 sl->tx_cnt = SLLIN_BUFF_DATA;
904 sllin_send_tx_buff(sl);
905 clear_bit(SLF_MSGEVENT, &sl->flags);
906 kfree_skb(sl->tx_req_skb);
907 netif_wake_queue(sl->dev);
909 sl->lin_state = SLSTATE_RESPONSE_SENT;
910 goto slstate_response_sent;
913 sl->lin_state = SLSTATE_RESPONSE_WAIT_BUS;
917 /* Be aware, no BREAK here */
918 case SLSTATE_RESPONSE_WAIT_BUS:
919 if (sl->rx_cnt < sl->rx_expect)
922 hrtimer_cancel(&sl->rx_timer);
923 pr_debug("sllin: response received ID %d len %d\n",
924 sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
926 if (sllin_rx_validate(sl) == -1) {
927 pr_debug("sllin: RX validation failed.\n");
928 sllin_report_error(sl, LIN_ERR_CHECKSUM);
930 /* Send CAN non-RTR frame with data */
931 pr_debug("sllin: sending NON-RTR CAN"
932 "frame with LIN payload.");
933 sll_bump(sl); /* send packet to the network layer */
936 sl->id_to_send = false;
937 sl->lin_state = SLSTATE_IDLE;
940 case SLSTATE_RESPONSE_SENT:
941 slstate_response_sent:
942 if (sl->rx_cnt < sl->tx_lim)
945 sll_bump(sl); /* send packet to the network layer */
946 pr_debug("sllin: response sent ID %d len %d\n",
947 sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
949 sl->id_to_send = false;
950 sl->lin_state = SLSTATE_IDLE;
955 hrtimer_cancel(&sl->rx_timer);
956 pr_debug("sllin: sllin_kwthread stopped.\n");
962 /************************************
963 * sllin_open helper routines.
964 ************************************/
966 /* Collect hanged up channels */
967 static void sll_sync(void)
970 struct net_device *dev;
973 for (i = 0; i < maxdev; i++) {
978 sl = netdev_priv(dev);
981 if (dev->flags & IFF_UP)
986 /* Find a free SLLIN channel, and link in this `tty' line. */
987 static struct sllin *sll_alloc(dev_t line)
990 struct net_device *dev = NULL;
993 if (sllin_devs == NULL)
994 return NULL; /* Master array missing ! */
996 for (i = 0; i < maxdev; i++) {
1003 /* Sorry, too many, all slots in use */
1008 sl = netdev_priv(dev);
1009 if (test_bit(SLF_INUSE, &sl->flags)) {
1010 unregister_netdevice(dev);
1012 sllin_devs[i] = NULL;
1017 char name[IFNAMSIZ];
1018 sprintf(name, "sllin%d", i);
1020 dev = alloc_netdev(sizeof(*sl), name, sll_setup);
1026 sl = netdev_priv(dev);
1027 /* Initialize channel control data */
1028 sl->magic = SLLIN_MAGIC;
1030 spin_lock_init(&sl->lock);
1031 sllin_devs[i] = dev;
1037 * Open the high-level part of the SLLIN channel.
1038 * This function is called by the TTY module when the
1039 * SLLIN line discipline is called for. Because we are
1040 * sure the tty line exists, we only have to link it to
1041 * a free SLLIN channel...
1043 * Called in process context serialized from other ldisc calls.
1046 static int sllin_open(struct tty_struct *tty)
1050 pr_debug("sllin: %s() invoked\n", __FUNCTION__);
1052 if (!capable(CAP_NET_ADMIN))
1055 if (tty->ops->write == NULL)
1058 /* RTnetlink lock is misused here to serialize concurrent
1059 opens of sllin channels. There are better ways, but it is
1064 /* Collect hanged up channels. */
1067 sl = tty->disc_data;
1070 /* First make sure we're not already connected. */
1071 if (sl && sl->magic == SLLIN_MAGIC)
1074 /* OK. Find a free SLLIN channel to use. */
1076 sl = sll_alloc(tty_devnum(tty));
1081 tty->disc_data = sl;
1082 sl->line = tty_devnum(tty);
1084 if (!test_bit(SLF_INUSE, &sl->flags)) {
1085 /* Perform the low-level SLLIN initialization. */
1086 sl->lin_master = true;
1090 sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
1093 sl->id_to_send = false;
1094 sl->data_to_send = false;
1096 sl->lin_baud = 19200;
1098 sl->lin_state = SLSTATE_IDLE;
1100 hrtimer_init(&sl->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1101 sl->rx_timer.function = sllin_rx_timeout_handler;
1102 /* timeval_to_ktime(msg_head->ival1); */
1103 sl->rx_timer_timeout = ns_to_ktime(
1104 (1000000000l / sl->lin_baud) *
1105 SLLIN_SAMPLES_PER_CHAR * SLLIN_CHARS_TO_TIMEOUT);
1107 set_bit(SLF_INUSE, &sl->flags);
1109 init_waitqueue_head(&sl->kwt_wq);
1110 sl->kwthread = kthread_run(sllin_kwthread, sl, "sllin");
1111 if (sl->kwthread == NULL)
1114 err = register_netdevice(sl->dev);
1116 goto err_free_chan_and_thread;
1119 /* Done. We have linked the TTY line to a channel. */
1121 tty->receive_room = SLLIN_BUFF_LEN * 40; /* We don't flow control */
1123 /* TTY layer expects 0 on success */
1126 err_free_chan_and_thread:
1127 kthread_stop(sl->kwthread);
1128 sl->kwthread = NULL;
1132 tty->disc_data = NULL;
1133 clear_bit(SLF_INUSE, &sl->flags);
1138 /* Count references from TTY module */
1143 * Close down a SLLIN channel.
1144 * This means flushing out any pending queues, and then returning. This
1145 * call is serialized against other ldisc functions.
1147 * We also use this method for a hangup event.
1150 static void sllin_close(struct tty_struct *tty)
1152 struct sllin *sl = (struct sllin *) tty->disc_data;
1154 /* First make sure we're connected. */
1155 if (!sl || sl->magic != SLLIN_MAGIC || sl->tty != tty)
1158 kthread_stop(sl->kwthread);
1159 sl->kwthread = NULL;
1161 tty->disc_data = NULL;
1164 /* Flush network side */
1165 unregister_netdev(sl->dev);
1166 /* This will complete via sl_free_netdev */
1169 static int sllin_hangup(struct tty_struct *tty)
1175 /* Perform I/O control on an active SLLIN channel. */
1176 static int sllin_ioctl(struct tty_struct *tty, struct file *file,
1177 unsigned int cmd, unsigned long arg)
1179 struct sllin *sl = (struct sllin *) tty->disc_data;
1182 /* First make sure we're connected. */
1183 if (!sl || sl->magic != SLLIN_MAGIC)
1188 tmp = strlen(sl->dev->name) + 1;
1189 if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
1197 return tty_mode_ioctl(tty, file, cmd, arg);
1201 static struct tty_ldisc_ops sll_ldisc = {
1202 .owner = THIS_MODULE,
1203 .magic = TTY_LDISC_MAGIC,
1206 .close = sllin_close,
1207 .hangup = sllin_hangup,
1208 .ioctl = sllin_ioctl,
1209 .receive_buf = sllin_receive_buf,
1210 .write_wakeup = sllin_write_wakeup,
1213 static int __init sllin_init(void)
1218 maxdev = 4; /* Sanity */
1221 pr_debug("sllin: %d dynamic interface channels.\n", maxdev);
1223 sllin_devs = kzalloc(sizeof(struct net_device *)*maxdev, GFP_KERNEL);
1225 printk(KERN_ERR "sllin: can't allocate sllin device array!\n");
1229 /* Fill in our line protocol discipline, and register it */
1230 status = tty_register_ldisc(N_SLLIN, &sll_ldisc);
1232 printk(KERN_ERR "sllin: can't register line discipline\n");
1236 #ifdef BREAK_BY_BAUD
1237 pr_debug("sllin: Break is generated by baud-rate change.");
1239 pr_debug("sllin: Break is generated manually with tiny sleep.");
1245 static void __exit sllin_exit(void)
1248 struct net_device *dev;
1250 unsigned long timeout = jiffies + HZ;
1253 if (sllin_devs == NULL)
1256 /* First of all: check for active disciplines and hangup them.
1260 msleep_interruptible(100);
1263 for (i = 0; i < maxdev; i++) {
1264 dev = sllin_devs[i];
1267 sl = netdev_priv(dev);
1268 spin_lock_bh(&sl->lock);
1271 tty_hangup(sl->tty);
1273 spin_unlock_bh(&sl->lock);
1275 } while (busy && time_before(jiffies, timeout));
1277 /* FIXME: hangup is async so we should wait when doing this second
1280 for (i = 0; i < maxdev; i++) {
1281 dev = sllin_devs[i];
1284 sllin_devs[i] = NULL;
1286 sl = netdev_priv(dev);
1288 printk(KERN_ERR "%s: tty discipline still running\n",
1290 /* Intentionally leak the control block. */
1291 dev->destructor = NULL;
1294 unregister_netdev(dev);
1300 i = tty_unregister_ldisc(N_SLLIN);
1302 printk(KERN_ERR "sllin: can't unregister ldisc (err %d)\n", i);
1305 module_init(sllin_init);
1306 module_exit(sllin_exit);